What can I do about the slugs that are devouring my hostas?
Slugs are more reliable than rain. Even in drought years, when it seems like every moisture-loving creature has packed up and moved to the coast, slugs continue to lurk under rocks, mulch, and garden debris waiting for nightfall when they happily devour everything from foliage to stems to ripening fruit.
Prevention is the best way to deal with most garden problems. In the case of slugs, this means allowing your garden to dry out between waterings, making it less appealing to slugs who like nothing better than to congregate in damp places. Raking up garden debris on a regular basis removes valuable daytime cover while pulling mulch away from the base of plants reduces their opportunity to inflict damage.
Hostas, as you’ve already figured out, are slug magnets. If you absolutely must grow them, consider picking a thick-leaved variety, such as Hosta seiboldiana, which slugs find less palatable than hostas with thin, easy-to-chew leaves.
By now I’m sure everyone knows that sinking a shallow dish filled with beer in the ground is a good way to trap slugs. (If your slugs are teetotalers, you can use fermented yeast instead.) Commercial slug traps, which are generally baited with fermenting grains or yeast, are also available and work on the same principle as the dish of beer. For some reason, slugs love fermented things to the point of drowning themselves in them.
There are other tried and true ways of getting rid of slugs. Ground beetles, garter snakes, toads, lizards, starlings, and centipedes all eat slugs. Attracting them to your garden can be as simple as mulching around your garden or establishing permanent walkways of grass or clover between your garden beds.
Some folks swear by copper strips to keep slugs out of their gardens. The copper interacts with the slugs’ mucous, creating a chemical reaction similar to an electric shock. Since these strips rely on those shocked slugs refusing to cross over the copper, they tend to work better on raised beds, planters, or tree trunks where you can cover a hundred percent of the circumference. Anything less and the slugs will find a way in. If they were already in the garden before you put the barrier in place – and really, why would you be putting the bands in place if they weren’t - you’ll need to evict them or the only thing the copper band will be doing is preventing the slugs from leaving.
You can also plaster your garden each evening with boards, overturned flower pots, grapefruit rinds, cabbage leaves, or cut raw potatoes and flip them over the following morning. Any slugs that have taken daytime cover under these homemade traps can then be removed and destroyed. Just remember to remove them every day or you’ll be providing resident slugs with valuable shelter and inadvertently aiding them in their mission.
If you have any questions or comments, please send them to me at vanessa@gardenmuse.ca.
